The subject matter disclosed herein relates to a surface cooler.
Typically, a surface cooler is installed in a wall of an aero engine turbofan bypass duct. Normally, the surface cooler is used to cool engine oil but can be used for cooling other fluids. This oil travels through an oil layer and secondary surface fins directly above the oil layer protrude into airflow moving through the bypass duct. The heat transfer between the airflow and the secondary surface fins leads to heat removal from the hot oil through a flat primary surface separating plate to which the secondary surface fins are connected and the secondary surface fins.
In general, the secondary surface fins have the same cross-sectional profile from front to back even though, in practice, the fins must serve different functions at different points. For example, the front section of fins must withstand impacts from foreign objects travelling through the bypass duct (e.g., hail), the middle section of fins must offer a high degree of thermal performance and the back section of fins must create smooth flow to minimise a wake produced by the surface cooler.